Why is the recording volume low and there is noise?

This is because the microphone is not connected to the phone successfully, and the recorded sound is 

coming from the phone's built-in microphone. Please check if the OTG cable is properly connected. To check 

if the microphone is connected to the phone, you can follow these steps: 

1. Long press the mode button on the transmitter for 2 seconds to switch to the reverb effect recording mode. 

2. Use the phone's voice recording function to record. If the recorded sound has reverb effects, it means the 

connection is successful.